CHEMOATTRACTANT INDUCED GENE EXPRESSION IN LEUKOCYTES

长期以来，白细胞趋化剂一直被认为是一组 引发特定细胞功能的促炎因子，如 趋化、脱颗粒、超氧阴离子生成及活化 整合素。最近的研究结果表明，化学诱导剂 还可以诱导促炎症细胞因子的合成和分泌 包括趋化因子，一种可能对启动至关重要的功能 和对局部细胞因子网络的调节和/或继续 白细胞向炎症部位募集。 从我们的研究得出的初步结果表明，假设 趋化因子诱导的核因子-kappaB活化是 细胞因子基因在白细胞中的表达。也有人推测， 趋化因子(Kappa)B诱导的信号转导途径 激活不同于其他核因子(Kappa)B激活 如肿瘤坏死因子(α)和PMA。目前的项目旨在测试 这些假设，并包含两个具体的目标。(1)性格特征 化学诱导剂刺激的信号事件导致转录 激活。这是应用程序的核心。我们的主要利益 是在鉴定化学诱导剂独有的机制上 (PAF，FMLP)刺激核因子-(Kappa)B活化。一个重建系统， 基于瞬时共转染质粒DNA，将被用于 鉴定另一种髓系分化相关因子 FMLP-(以及C5a和IL-8)诱导的核因子-(Kappa)B所需的 激活。(2)调查的范围和变异性 趋化因子刺激的单核细胞基因表达 中性粒细胞(PMN)。在这个特例中，我们将检查 单核细胞和中性粒细胞对基因的作用机制是否相同 对化学诱导剂刺激有反应的表达。我们还将测试 IL-8的概念是通过结合多种基因来调节自身的基因表达 IL-8受体与核因子-(Kappa)B的激活 目标将扩展我们目前对生理学的理解 化学吸引剂的功能，是我们长期工作的一个组成部分 与白细胞分子机制有关的研究目标 激活。

Leukocyte chemoattractants have long been regarded as a group of proinflammatory factors that trigger specific cellular function such as chemotaxis, degranulation, generation of superoxide anions and activation of integrins. Results from recent studies indicate that chemoattractants can also induce the synthesis and secretion of proinflammatory cytokines including chemokines, a functions that may be crucial for the initiation and regulation of a local cytokine network and or the continued recruitment of leukocytes to site of inflammation. Preliminary results derived from our studies suggest the hypothesis that chemoattractant-induced NF-kappa B- activation is a primary mechanism for cytokine gene expression in leukocytes. It is also postulated that the signaling pathways leading to chemoattractant-induced NF(kappa)B activation differ from that utilized by other NF(kappa)B-activating agents such as TNF(alpha) and PMA. The current project aims to test these hypothesis, and contains 2 specific aims. (1) Characterization of chemoattractant-stimulated signaling events leading to transcription activation. This is the core of the application. Our primary interest is in the identification of mechanisms that unique to chemoattractant (PAF, FMLP)-stimulated NF-(kappa) B activation. A reconstitution system, based on transient co-transfection of plasmid DNA, will be employed to identify an additional myeloid differentiation-association factor required for FMLP-( and also C5a and IL-8) induced NF-(kappa)B activation. (2) Investigation of the extent and variability of chemoattractant-stimulated gene expression in monocytes and polymorphonulear neutrophils (PMN). IN this specific we will examine whether monocytes and neutrophils employ the same mechanism for gene expression in response to chemoattractant stimulation. We will also test the notion IL-8 can regulate its own gene expression through binding of the IL-8 receptors and activation of NF-(kappa) B. Achievement of these goals will extend our current understanding of the physiological functions of chemoattractants, and is an integral part of our long term research objective relating to the molecular mechanisms of leukocyte activation.